Automatic vaporizer for hot-water heating systems



M. HOUCK.

AUTOMATIC VAPOHIZER FOR HOT WATER HEATING SYSTEMS.

APPLICATION FILED JAN.29. 1917.

1 344, 894 I Patented June 29, 1920.

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AUTOMATIC VAPORIZER FOR HOT WATER HEATING SYSTEMS.

APPLICATION FILED JAN. 29, I917.

1 344,894. Patented June 29, 1920.

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151 has fliiorneys UNITED sTA Es PATENT OFFICE.

MARTIN HOUCK, OF MINNEAPOLIS, MINNESOTA, ASSIGNOR TO VACUUM HEAT MANU- FACTURING COMPANY, OF MINNEAPOLIS, MINNESOTA, A CORPORATION OF MIN- NESOTA.

AUTOMATIC VAPORIZER FOR HOT-WATER HEATING SYSTEMS.

Specification of Letters Patent. Patented June 29, 1920.

Application filed January 29, 1917. Serial No. 145,110.

To all whom it may concern:

Be it known that I, MARTIN HOUCK, a citizen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Automatic Vaporizers for Hot-VVater Heating Systems; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relatesparticularly to gravity hot water heating systems, and is directed to the provision of a simple and highly eflicient vaporizer, socalled, by the use of which the advantages of a vapor heating system is obtained without the resulting disadvantages of such vapor systems. Generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims. I

The objects of the vaporizer, when installed in a hot water heating system, is to provide and maintain a reduced pressure throughout the heating system, by the utilization of the atmospheric pressure to partly or entirely support the weight of the water in the heating system. The resulting reduction in pressure incident to the use of this vaporizer enables the water in the system .to be vaporized at low, temperature, the vapor condensing in the radiators giving off its latent heat of vaporization in so condensing. Provision is made in the vaporizer or in parts associated therewith, whereby there will be an automatic discharge of water from the system when the pressure therein exceeds a certain maximum predetermined pressure, and this prevents boiling of water in the system. Provision isalso made for automatically returning water to the system when, through the subsequent cooling of the water, an initial vacuum or void is formed in the system of sufiicient intensity to endanger leakage of air into the high points of the heating system. These matters, however, will be more readily understood after a commercial form of the apparatus has been considered more in detail.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Figure 1 is a view chiefly in side elevation but with some parts sectioned, showing the improved vaporizer applied to a gravity hot water heating system; and

Fig. 2 is an enlarged view of the vaporizer partly in elevation and partly in vertical section.

Of the parts of the hot water heating system, the numeral 4 indicates one of the radiators, the numeral 5 indicates the hot water feed pipe from the boiler 3 to the radiator and the numeral 6 the cold water return pipe, all of which parts may be of the usual or any suitable construction and arrangement. The numeral 7 indicates a pressure gage and the numeral 8 a thermometer applied to, the top of the boiler, in the customary way. The vaporizer may be connected to the water circulating system at different points and in Various different ways, but is preferably located in the basement and connected tothe lower portion of one of the cold water return pipes, although it might even, in this preferred location, be connected directly to the boiler. I

Describing the said vaporizer illustrated in the drawings, the numeral 9 indicates a pipe which is preferably, although not necessarily, connected to a supply of water under pressure, such as to one of the supply pipes of a city water system. This pipe 9 is provided with a normally closed valve 10. From a pointbelow the valve 10, a pipe 11 extends laterally from the said pipe 9 and taps one end of a check valve casing 12, the passage of which is normally closed by an upwardly open check ball 13. The outer end of this valve casing 12 is connected by a short pipe 14 to a reducing hollow head or T 15. The head 15 is connected to the upper end of an outer tube 16, the lower end of which is tightly closed by a cap or plug 17. A

The tubes 16 and 18 constitute a trap and they contain mercury y. The top of the trap relief chamber 20, as shown, is connected by a tubular 'thimble 21 to the lower extremity of a bulb-like expansion chamber 22. The lower extremity of this chamber 22, however, does not directly communicate with the nipple 21, but the upper portion thereof is connected therewith through a tube 23 that is screwed into the said nipple at its lower end and terminates near the top of said chamber 22. A bent pipe 24 extends from the top of the expansion chamber 22 and. is provided with a check valve 25 26. The extended end of this pipe 24 opens to the atmosphere and may be extended to any suitable drain, if desired. The ball 26 is gravity-seated and permits outward flow through the pipe 24, but checks a reverse flow.

Thelower portion of the expansion chamher 221 is connected by a pipe 27' to the pipe 11 at a point inward of the check valve 1213; and as this pipe 27 is interposed in a check valve made up of a casing 28 and gravity-seated ball 29 that permits flow from the expansion chamber 22 to the pipe 11, but checks a reverse flow.

Here it may be stated that the check valve 2526 and tube 23 are not essential features and may be dispensed with. If the check valve 26 is: employed, it must be a leaky check valve 'or some arrangement made for the slow passage of air from overflow pipe 2 1 backinto expansionchamber 22. The only useful function. that will be performed by this soecalled leaky check valve 25-26 would be to render slow the inward flow ofairfrom pipe 24.

Operation.

In the following described operation, check valve 25-26 will be ignored and it will be assumed that there is afree return of air from pipe 24C, rather than the restricted or retarded flow, for the operation will be the same except, in point of time required for certain equalizations of pressure totake place. When city water pressure, for example, is applied to the system by opening of valve 10, the system, including the radiators, will be filled with water, assuming, of course, that air valves in the tops of the radiators are opened to permit of the displacement of air therefrom. The city or other external water pressure is then shut offand the'system becomes a closed system in which an: expansion tank is not required, but from which, water may be ejected under abnormally high pressure, through the so-called vaporizer. The gage on the boiler will then indicate the head of water above the gage, as measured above atmospheric pressure.

The gage employed will preferably'be a gage that will indicate zero at atmospheric pressure. The above pressure may be greater than the net pressure of the mercury column on the vaporizer acting 011 the water, in which case the mercury willbe forced out of the tube 18 and into chamber 20. If. this action is not produced by the static pressure in the cold steam it will later on be produced in actual operation when the heat in the system is sufficient to produce a pressure that will overcome and lift the column of mercury into the chamber 20, as above stated. Chamber 2() being of much larger cross section than tube 18, allows the mercury to spread out with the result that the depth of the mercury is reduced. The water pressure will then be considerably greater than the resisting head of'mercury in chamber 20 and the water will then be forced through the mercury until such an amount has been discharged that the pressure in the system will drop to a point where it will be unable further to force water through the mercury. hen this point is reached, the

water will cease flowing and the mercury will drop back in tube 18 and into the lower portion of tube 16, but this backward pressure can not exert itself on the system because backward flow of water from tube 16 and pipe 11 is prevented by check valve 12-13.

lVhen the water, in the system, by cooling, reaches such a point that the pressure approximately at the altitude of check valve 2829 is below atmospheric pressure, as indicated by zero on the pressure gage, water will reenter the system from chamber 22 through check valve 28-29 until atmospheric pressure is again restored at the altitude of said valve.

Referring to' Fig. 1, it willbe seen that the pressure, actingon the mercury in tube 16 will theoretically never be less than atmospheric pressure in such system where the total height of the water in the system will be less than thirty-four feet, the height capable of being sustained, theoretically, by atmospheric pressure. This is due tothe fact that atmospheric pressure is exertedon the water in chamber 22 and is conveyed to the mencury in tube 16' through the check valves- 28-29 and 121'3; Before the discharge of water takes place from the system, the pressure in tube 16 must be greater than atmos pheric pressure, but after initial discharge produced, for example, by first heating-up the system to a very high temperature, towit, a temperature preferably about that which will subsequently take place in the normal operation in the system, there will not be a further discharge of water sufiicient to overflow through pipe 24: unless there is leakage of air into the high point of thesystem, resulting in. lowering the column of water. lVhen there is such ailowering of the column of water there may be a further disthereof to the system through pipe 27 and check valve 28-29. Slight variations in pressure in the system, however, may not force the mercury entirely into chamber 20, but, nevertheless, each slight increase in pressure in the system will force some water through check valve 12-13, and as this water cannot return through said check valve it will be caused to raise the mercury in tube 18 above the lower extremity thereof and the mercury will drop back, causing the water to be displaced and delivered into chamber 20 and sooner or later into chamber 22, and moreover, each cooling of the water and resulting'contraction will return water to the boiler through check valw 2829. Thus, atmospheric pressure is automatically maintained in the system approximately at the level of check valve 2829, but this altitude of atmospheric pressure will be varied slightly by the difference in the alti; tude of water in chamber 22. The statement made that atmospheric pressure will be maintained approximately at the altitude of the check valve 28-29, is, however, sufficiently accurate for all practical purposes and accomplishes the main results sought by the applicant, towit, the maintenance of approximately atmospheric pressure in the boiler. Hence, it is important that this so. called vaporizer be applied approximately at the altitude of the upper portion of the boiler, or, at least, in the basement with the boiler. Nevertheless, it might be applied higher up with beneficiary, although not as good results as when applied as now advised. It may add to the understanding of the operation of this system to further state that if the high point of the water column be ap proximately thirty four feet from the above indicated altitude of atmospheric pressure, then there will be, theoretically, approximately a perfect vacuum or absolute zero pressure at the high point of the system. If the high point of the system is less than thirty four feet, the pressure'in the high point of the system will be above absolute zero. For example, if the column of water above the atmospheric pressure line is six teen feet, then there will be approximately one-half atmospheric pressure at the high point of the water column, but always, there will be maintained approximately atmospheric pressure at the point of discharge from the vaporizer. Thus it will be seen that the column of mercury exerts a force that must be overcome, to a greater or less extent, before there will be a discharge of water from the system, but this column of mercury does not exert a re-acting force on the system when the pres sure at the altitude stated is atmospheric or less, because ofcheck valve 1213.. Obviously, there can never be a discharge from the system through check valve 28-29 but there can be return of water from chamber 22 to the system whenever the pressure in the boiler is below atmospheric. Hence, the column of water in the heating system is always supported by a pressure not less than atmospheric pressure, and by this action alone, the tendency for leakage of air into the system is prevented. However, the main object accomplished is a relatively low pressure in the boiler which permits vaporization at approximately atmospheric pressure,

and this results in the following advantages:

1. The heat content of vapor is far greater than the heat content of an equivalent volume of water. For this reason, a given surface of radiation will give off more heat when inclosing vapor or mixed water and vapor, than when inclosingwater alone.

2. From the above facts, it' is self-evident that in systems equipped with the vaporizer, less radiation is required for producing a given amount of heat, or, for a given amount of radiation, a higher room temperature can be produced. a

3. The rate of heat transmission of radiators or pipes is greater per degree difference in temperature for vapor, than water hence less time is required in attaining a certain temperature with systems equipped with the vaporizer. I

4. Due to the increased rate of heat transmission of the radiation as mentioned above, the boiler will not have to be forced to such a capacity in severe weather as to impair its efficiency, and a consequent saving of coal will result.

5. A further saving in coal can be effected due to the fact that there is a rapid transfer of heat from the boiler to the radiating surfaces, whereas, in a hot water gravity system, it is necessary to change the temperatures of the entire volume of water in the system before sufficient heat transfer occurs, requiring a comparatively longer time. In the vapor system, quicker regulation of the heating medium can be effected to correspond to the temperature changes of the outside air. I

In general, it may be stated that systems equipped with the vaporizer, combine the good qualities of both hot water and vapor systems, without their defects.

The following comments are further perthe required functions, towit, of permitting an easy or but slightlyresisting flow in the one direction and an impossible or diflicult flow in the reverse direction.

What I claim is:

1. The combination With a hot water heating system including a boiler, of a trapping chamber open to the atmosphere, a discharge pipe connecting the water circulating system to said trapping chamber, and a check valve in said discharge pipe arranged to permit flow from the circulating system tosaid trap but to check a reverse flow, whereby the weight of the column of liquid in said trappin chamber is prevented from re-acting on t 1e circulating system when the pressure in the system approximately at the altitude of the trap is below atmospheric.

2. The combination of a hot water heating;

system including a boiler, of a trapping chamber open to the atmosphere, a discharge pipe connecting the water circulating system to said trapping chamber, a pressure seated check valve in said discharge pipe permitting flow from the system to said trapping chamber but checking a reverse flow therethrough, a return pipe from said trapping chamber to the Water circulating system, and a check valve in said return pipe permitting a flow from said trap back to the circulating system but checkinga reverse or outwardfiow therethrough.

holds the same seated under very considerchamber at the upper extremity of one leg of said mercury trap, a dischargepipe connecting the other leg of sald mercury trap to the. Water circulating system, a check.

valve in said discharge pipe permitting'flow from the system to said mercury trap but checking a reverse flow, a Water trapping chamber connected to and extended above said relief chamber, said water trapping chamber being open to the atmosphere.

4. The combination with a hot Water heating system including a boiler, of a mercury trap containing mercury, an expanded relief chamber at the upper extremity of one leg of said mercury trap, a discharge pipe connecting the other leg of said mercury trap to the water circulating system, a check valve in said discharge pipe-permitting flow from the system to said mercury trap but checking a reverse How, a water trapping chamber connected to and extended above said relief chamber, said water trapping chamber being open to the atmosphere, atits upper portion, a return pipe connecting said water-trapping chamber to the circulating system, and a check valve in said re turn pipe permitting a return flow from said water trapping chamber back to the circulating system but checking a reverse or outward flow therethrough.

In testimony whereof I afiix my signature in presence of two witnesses.

MARTIN HOUCK Witnesses:

HARRY D. KILcoRE, F. D. MERCHANT. 

